Process and apparatus for rolling glass



Apr; 13 1926. y Gc. oAKEs PROCESS AND APPARATUS FOR RCLL'ING GLASS Filed July sa, 1925 2 Shgmsnsmi 3.

rr-Gym,

Apri 13 1926.

G. C. @AKES PROCESS AND APFARATUS FOR ROLLEG GLASS Filed July sa, 19.25

2 Sheets-Smet 2 A mu To yaZZbw/zom 'it may concern rolls for short periods,

the glass flows through the Aroll pass 1n a.`

r islmaterially improved.

Patented Apr. 13, 192s.

UKIU'IJ'ED STA TES eAfreurvorrics.,

.oneven c. oni/ins, or cnEIGHToN, PnNNsYLgANrA. AssIGNon' To PITTSBURGH PLATE oLAss COMPANY, A coneonATroN or PENNSYLVANIA. 1`

IPRQCESSl AND APPARATUS FOR'ROLLING GLASS.

Application filed Juuly S, 1 925. Serial o. 42,490.

Be it known that I, Gnovnn C.y OAK-ES, a citizen of the United States, and a resident of Creighton, in the county of Allegheny and State of Pennsylvania, have made a new and useful invention in Improvements in aS Process and Apparatus for Rolling Glass, of which the followingfis a specification.

The invention relates to a process and epparatus for rolling glass in` a continuous ribbon or sheet as a step in the-manufacture of plate glass. It has for its object, thcpro# vision I ofl a procedure and construction whereby the quality of the-glass produced YIn the process of rolling glass continuously from a tank, it has? been "found that after a period of op eration, which varies considerably in lengt i, bubbles, deviti'ified glass and other defects commence to show in the glass in increasing quantity. It is, believedv that this is due to the conditions which exist in the bath just 4back ofthe rolls, at which point the walls of the outlet slot through which the glass `is passing tend to stopjor retard the flow, and thus cause an accumulation of the bubbles which are scattered through the glass. Such bubbles may also he actually formed at this point.' due to a reaction between the'y glass and the clay walls of the slot. Due also to the chilling; eiiiect of the. outlet slot, and of the rolls themselves, `a loyer of. Arelatively thick viscous glass is retained by such walls, and in the course of time, this glass becomes devitriied. This glass is fina-ily carried through the rolls and shows as cloudy streaks or bands.

Iihave found that this unfavorable condition may' be overcome and glass of high quality produced, even after a long period ofoperation, by a procedure which has been aptly described as dusning the rolls. This is nccoinplishediby periodicfilly separating the during which periods,

thick stream carrying with it any accumulation of bubbles and also washing away any layer of more viscous glass which may here beer accumulating along the clay surfaces just baci; of the rolls. This flushing operation may be carried out'erery hour 'or two v(the exact period dependiugjon condieno ordine? 't7 o about one' ha@ i i iu this position while `a body of ,glass from eight to twelve inches long flows through, the width of the opening and the. length of the period also depending on conditions. The. thickenedsections of glass thus formed contain 'fthe' maj or portion of an'y bubbles and chilled glass (either 'devitriiied or on the wey to be come such) which would eventually enter into and be scattered through the ribbon'if n otcollected in this manner, and Such sections are. cut from' the ribbon as waste glass after 1t emerges from the leer through whichit is conducted from'the rolls. riety" ofmechanisin may be providcdrfor carrying out this iiushing step, and infact, no particular means need be provided, asit is always possible to kmove one of a-pair of sizing rolls away from the other.' It isidesirable, however, to provide 'anarrangement whereby the periodic flushing;` may be accomplished by the -attendante` easily yand conveniently, and without any requirement for resetting ofwthe movable roll after the' operation is completed', and twoforms of mechanism, as `designed for this purpose, `are illustrated inthe accompanying drawings;4

wherein:v Y f Figure'l 1s a vertical sectionon the line Referring to the 'drawingnliis the for-y ward or outlet end of a melting tank, preferably of the regenerator type and provided with a front wall 2 having an outlet slot 3. The outlet end of the tankmay be' cut off from the rest of the tank by means of the gates 4 and 5 supported from above upon a crane by means of the depending chains 6 and 7; the. gate 4 being' of metal and water cooled and the gate 5' being' of lrefractory material such as clay. K'

Forward of the outlet slot 3 are. apair of forming or sizing rolls 8 and 9, preferably driven and water cooled and adapted to form the'molten glass into s ribbon 10 which is re ceive'd upon a runway made up-of the series of rolls 1l, 1Q, 13, etc. These rolls and also the rolls 8 and 9 are carried upon assuitable framework le mounted upon the carriage l5, such carriage being adapted to be moved elle will be sepa.-4 laterally from its position' in front of the tank to a position at one side thereof. For- A lwide Vaward of the roller runway is a leer, not shown, which receives the sheet or ribbon and takes care of the annealing and gradual cooling of such sheet, the glass being cut into 5 sections at the far end of the leer.

The rolls 8 and 9 are journaled at their ends inthe bearing blocks 16 and 17, which bearing blocks are suitably guided and supported in.th'e standards 18 carried by the .1U framewor'; 414. Intermediate the bearing blocks 16"and 1-7 at each end of the rollsis a roll spacing wedge 19 which hasthreaded .into its end the operating'screw 20. This screw isswiveled in the standard 18 as in.- jdieat'e'dat 21 (Fig. l),

V of thescrew is provided with a square end 22 for receiving wrench or other suitableA handle for rotating the screw. By this means, the distance between the rolls may be yregulated tov give the desired thickness of sheet and to maintain the `rolls in parallelism. The rolls are provided with swivels at their ends, |to which are connected the water pipes 23 ,and 24 for giving a cineula- 5 tion of water, and the driving of the rolls is accomplished by means ot the tumbler shafts 25 land 26 (Fig. 2) vconnected to suitable driving means, not shown.

The upper roll 8 is yieldingly held 1n position by means of a spring 2T at each end bearing against the blocks 16 and having its pressure regulated by means of the screws 28 extending through the blocks 29 bolted to the upper-ends ofthe standards 18, as

" indica d in Fig?. 1. -At each end of the roll 8 a stirrup 30 is provided encircling the end of the roll just outside the bearing block 16, the upper end of each stirrup being bolted to a U shaped block 31 rthrough which extends a threaded pull rod 32. Each pull rod is provided at its upper end with a head 33,

which is engaged -by the hook end 34 of a lever having th long arm 35.

such shaft being journalcd in brackets bolted to the cap plates 29 of the standards 18. rlhe longl end 35 ot' the lever is form of a fork having the slots 37 and between these ends is mounted a sleeve 38 provided with a pair ot laterally extending pins lying in such slots. This sleeve telescopes loosely over the threaded rod 39 pivoted at its lower end to the bracket 4() and is adapt ed to be moved down by means of a hand wheel 41 having threaded engagement with the rod. By the use of this hand wheel, the lever may be` operated t0 litt the roll 8 against the pressure ot the spring 27 and thus permit the passage between the rolls of a relatively thick layer of glass, as heretotore referred to.

Provision is1 also made for this same function by the use ot' either one or both of the levers42 and 42 which nrc 6 mounted upon the ends ot' the square shaft accomplishing and the outer endi clinging This lever is r mounted near one end ot' the square shaft 36,

made in the means of atpipe 48 1,sso,1 sev 36. The leverage is such that an operator at either end of the rolls can easily raise the roll 8 to permit the Hushing action by graspingthe end of the lever 42er the end of thelever 42a and pulling such lever down so VI0 as t'o raise the roll 8 thgmdesireddistance.

The distance which the roll 8 is lifted to4 give the desired flushing eiect, and the 'time which such vroll is maintained Yin lifte'd'posil tion will vary depending upon conditions. Ordinarily, if a ribbon 1%, in thickness is being rolled, the distance which the roll' 8 will be raised for flushing is about 1%, more, so that a layer of glass 3/4 in thickness will pass between the rolls as long as they are 30 kept in separated position. ordinarily be kept separated distance to permit a layer of long to pass therethrough. llt has also been found desirable, although not necessary, to 35 repeat the flushing action several times at short intervals and then allow the rolls to operate in the usual Way for about 2 hours.V

his is merely by way of illustration, as the desired result involved in getting `rid of 90 any accumulated bubbles or viscous,I glass 1to the lips of theoutlet slot inay be accomplished bv timing the fiushingzoperaw tions and prolongingr them" in a Wide varietyl ,When theoperating levers"area5 The rolls will this increased glass about'12` ot'` ways', released permit the roll 8 to move-back to its` original position, the spacing apart (if` the rolls, remains the same as before the lushing'operation, due to the use offthe Wedges 19which limit the downwardinove lo@ ment otithe upper roll. The Weightv hflthe roll 8 1n conjunction Witht-h springs '27 insure that the upper roll will be pressed down with such firmness the WedgeS'lS so that the thickness of. the los sheet produced is not affected by `the stilness of the 'glass passingtherebetweeny t Eig. 3'illustrates another metho'diof actu-i ating the. lever arm 35 in place of the hand-i wheel 41. i 43 and a piston 44, the latter of which isi-cone* nected to the bracket 45` by means oftht rod `46. 'The forked end of the arm 35y i straddles the cylinder and `is engafred byaF pairl ofi pivots 47 projecting laterally the cylinder walls. The lower end'` of the cylinder below the piston is supplied` witt iiuidunden pressure, such as air or Water b i provided with a three 'y way valgve 49. Upon admitting fluid` undrmo pressure' through the pipe 48. the cylinder 43 is moved down to lower the arm 3`5 and thus raise the roll which is supported troml` the hook end 34 of the lever; The roll is i lowered afterthe flushing operation by move F252 `ing the threetway valve 49 to exhaustI posii` t tion, so that the tiuid in thecylindei beneatli tthe piston allowed to escape. :A WideV that its nds engage variety ot me hanisin 'might be employed for moving then This means includes a` cyliindeif im' fro-mi, 1.15`

iper roll 8 t0 ilushingpositiull, ,130i

rating the rolls to4 permit a' body of glass to pass therethrough of a thickness in excess of that of the ribbon which is being pro-l duced. y

2. A process for aking plate glass which consistsl in flowing it contini'iously from'a body of molten glass' under the headV pressure thereot` between a pair of sizing rolls set to produce alribbon or sheet of a definite thickness, and periodically separating the rolls for short intervals to permit the passage of sections of glass which are much thicker than the normal thickness of the sheet or ribbon.

3. In combination lin apparatus for making plate glass, a tank containing a body of molten glass, and having'an outlet leading through the Wallofthe tank, a pair of sizing rolls in opposition to one of the rolls and tending to maintain the'pass between the rolls of a constant the width, and power 'means for `separatin rolls against the pressure of said yie dinff means to 'permit Athe passage therethrougi of a body of glass of a thickness greater than 'sizing rolls in .opposition 'means to widen the pass .means for applying rolls to press it toward the other roll, means of said spring 1 .'means, adjustable v.stop meansfor limiting to said outlet', yielding meaiisar'ranged to apply pressure. us

-ro .t

In testimony' whereot,` I .have hereunto this 2nd day of July,

that of the ribbon or produced. i

4. In combination in apparatus for making plate glass, a tank containing a bo of moltenA glass,-and' having anvoutlet leading through the` wall of the tank, 'a pair of sheet which is being spring means for applying pressure to .one of the rolls to press it toward tlieother roll, means for ad]usting the pressure of'said spring means, and lever means for moving the spring pressed roll away from the other roll againstV the pressure of said spring` between the rolls. 5. In combination in apparatus for making plate glass, a tank co'ritafining'a body of molten glass,andihaving an outlet leading thro-ugh the wall of the tank, a pair of siz ing rollsin opposition to said outlet, spring lpressure to one ofthe for adjusting the pressure the movement of the spring pressedroll toward the' other roll, and' lever means for moving the spring pressed rollaway from the other roll against the pressure of said spring means to 'widen subscribed my name eRovER c. Oakes.v

to said outlet,

the `pass between the 

